Oliver tends to get a bit more credit than he perhaps deserves as the inventor of this type of gnomon. See for example Lloyd Mifflin's U.S. Patent 64892 (May, 1867) of an Equating Solar Chronometer - the key element of which is the analemmic gnomon.
Fred Sawyer On Wed, Sep 24, 2008 at 10:01 AM, Thomas Steiner <[EMAIL PROTECTED]>wrote: > Dear all, > > I tried to collect information on Martin Bernhardt's special Gnomons > which takes into account the equation of time in a equatorial sundial > on a single scale to read off time, regardless of the date (almost - > once a year the gnomon has to be changed). > The idea is good and simple: just rotate half of the analemma (ok, a > projection) around an axis. The original idea came from John Ryder > Oliver (1834-1909) and Bernhardt lived from 1919 until 2000. It's > incredible that this was discovered that late. Do you know any sources > or other information on it? Do you know of any ideas/inventions that > were close? What did Oliver exactly do? ... > > For the German speaking among you, I wrote major parts of this smal > wikipedia article: > http://de.wikipedia.org/wiki/Bernhardtsche_Walze > > Thanks for help on anything related to the subject... > thomas > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > >
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